2. Lead-Free large rifle primers had a “a much larger variation in peak blast pressure” than did lead-based large rifle primers.

3. Field tests showed 7.62×51 rounds loaded with lead-free primers to be less accurate than rounds loaded with lead-based primers.

4. So-called “match-grade” primers were NOT always more consistent in pressure than standard primers.

Russian Lead-Free Primers Tested
WSTIAC scientists did some pretty sophisticated testing, measuring the blast waves of lead free primers vs. standard primers. The lead-free primers, denoted as DDNP for their “Diazodinitrophenol” active ingredients, were matched up against commercially-available primers containing lead. Eight models of widely-used, lead-based primers were tested along with two DDNP-based Russian-made primers, a large rifle primer (model KVB-7E) and a small pistol primer (model KVB-9E). Brief field tests were also conducted with large rifle primers in loaded ammunition. Testers measured primer ignition times, bullet muzzle velocities, and accuracy on 200m targets.

Lead-Free Primers Were Less Reliable, with Less Uniform Pressure
While you’ll need to read the study to understand the full results, in a nutshell, the DDNP (lead-free) primers proved somewhat less reliable than standard primers. The study observed: “The most obvious difference between the lead-based and DDNP-based primers was a perceptible delay between firing pin strike and ignition in 15 of 19 shots with the DDNP-based primers (and one misfire); in contrast, there were no misfires or perceptible delays in ignition with the lead-based primer.” The scientists theorized that: “The delay in ignition in 6 of the 10 shots with the DDNP-based primer suggests that this primer is at the low end of strength needed to reliably ignite 46 grains of an extruded powder.” The study also noted that: “DDNP-based KVB-7E has a much larger variation in peak blast pressure than other primers.”

Lead-Free Primers Were Less Accurate in 7.62×51 Ammo
One very interesting finding related to accuracy. In field tests, 7.62×51 ammo loaded with lead-free primers was tested against ammo with lead-based primers (other components were identical). At 200m, the average 10-shot group size of 7.62×51 ammo with lead-free primers was 2.5 MOA vs. 1.8 MOA for ammo with lead-based primers. That 0.7 MOA difference may well be meaningful (though we’d like to see the test repeated with multiple 10-shot groups, fired from a more accurate rifle). For precision shooters, this is a provocative finding because it suggests that a change in primer type, by itself, may have a dramatic impact on accuracy. The scientists surmised that: “ignition delay is the most likely cause of the larger average group size.”

“Match” Primers Are NOT Always More Consistent
One surprising collateral finding in the study challenges the widely-held notion that “Match Primers” are better, at least when judged by pressure uniformity. “Table 1 shows average peak pressures along with standard deviations from the mean for the primers in this study…. There are significant differences in the standard deviations observed for different primer types, and it is notable that so-called ‘Match’ primers are not always more consistent than non-match primers.” Readers should look at the bottom right of Table 1 below. Note that, as a percentage (%) of total pressure, the non-match CCI 450s have a significantly lower SD than the “Match” Fed 205m primers. On the other hand, the Federal 210M and 215M “Match” primers ARE more uniform in pressure than the non-match CCI Large Rifle primers.

ABSTRACT: Comparing Blast Pressure Variations of Lead-Based and DDNP (Lead-Free) Primers
This article describes the blast pressure waves produced by detonation of both lead styphnate and diazodinitrophenol (DDNP) based firearms primers measured with a high-speed pressure transducer located at the muzzle of a rifle (without powder or bullet). These primer blast waves emerging from the muzzle have a pressure-time profile resembling free-field blast pressure waves. The lead-based primers in this study had peak blast pressure variations (standard deviations from the mean) of 5.0-11.3%.

In contrast, lead-free DDNP-based primers had standard deviations of the peak blast pressure of 8.2-25.0%. Combined with smaller blast waves, these large variations in peak blast pressure led to delayed ignition and failure to fire in brief field tests.

JCB – Actually, Russian (Wolf) traditional primers score very well in Cast Bullet Assc. benchrest matches. Those shooters would beg to differ with you.
That said, I agree with your comment about the limited sample of Russian only. Maybe they just have not got it right yet.

These results are not surprising, and I wouldn’t attach much importance to them. Note that for Table 1 figures it mentions sample sizes of 10 (shots with each type of primer). To attach any significance to SD as a percentage of the mean for samples of this size is statistically non-sensensical. Note that the authors (both PhDs) of the report don’t make any such claims, and that would be because they are aware of the limitations of the data. So I wouldn’t advise all you CCI large primer users to rush out and change to Federal based on these figures. By my reckoning, there’s a reasonable chance the true situation could be completely reversed.

The SDs of the small primers are not significantly different from each other (in the strict statistical sense of “significant”.)

The SD of the DDNP-based large primer is significantly larger than the lead-based primers.

The difference in primer strength among the lead-based primers is more interesting and relevant than the differences in SDs. Note, for example, how much stronger the Rem 7 1/2 is than the other small primers. Also note the strength of the Fed215M and CCI 250. I recently obtained outstanding consistency in Trail Boss using the CCI250 because I followed a recommendation for a stronger primer to improve consistencies in velocities. Who would have thought velocity SDs in the 5-12 fps range would be possible with Trail Boss?

We are eager to test the other DDNP primers as soon as they are available.

I haven’t reloaded in years, but would like to start again and thought I’d look into this primer issue. So who makes the best rifle primers today for accuracy, and do they have lead? As I age I get a little dummer every year and sure don’t need to breathe more lead “dust” to make it worse. Other than wearing a mask while shooting, I’d still like to benchrest like Tony Boyer. So the question is, use a lead primer or not?

I’ve used > 5000 Fiocchi Lead Free Small Pistol primers for action pistol shooting and have had great results, no problems. More expensive, but not as expensive as to treat high lead levels from high-volume shooting.

For those who are of a mind-set that Russian primers ; ( bullets , powder , cases , etc..) are junk , or inferior products , you only need to look back thru history when the Russians were dominating many types of competition with their “inferior” components .
And I am one F-Open / F-TR shooter who will happily purchase your Wolf primers to compete with . As are the majority of F-class shooters nationwide . Top level F shooters know that Wolf is one of the most consistent primers available , both for SD and ES , or they would not be so highly sought after within the community .

If you read Laurie Holland’s Small and Large rifle primer study ; Target Shooter Magazine – UK , the data he collected reflects that currently , The S&B primers rated much higher over-all than even the Federal , and other so-called “rated” competition primers .